Method for operating a motor vehicle alternator-starter

Abstract

A method for operating a reversible polyphase rotating electrical machine (2) in a motor vehicle which consists in performing the high-level and low-level management of the machine with a remote-control unit (1), which exchanges physical data, via a plurality of links (3) with a power module (20) integrated in or immediately proximate the machine (2). The method and electrical machine may be an alternator-starter.

Description

FIELD OF THE INVENTION[0001]The present invention concerns a method for making a reversible polyphase rotary electrical machine for a motor vehicle function.[0002]The invention concerns in general terms the choice of the electronic architecture and the management of the functioning of reversible polyphase rotary electrical machines such as alternator starters.[0003]The invention finds applications in particular in the field of motor vehicles. It applies more generally to the control of any alternator starter, or motor alternator, or motor alternator starter, with direct drive or by belt.PRIOR ART[0004]In a conventional alternator (that is to say non-reversible), there exists a regulator whose role is to regulate the voltage of the on-board system whatever the current output by the machine. The regulator may be of the controlled type. It is then interfaced with a control box, in particular an engine control box, by means of a low throughput link, for example a LIN link (Local Interco...

AI Technical Summary

Benefits of technology

[0015]Thus the invention makes it possible to avoid the use of cables on which high electric powers are conveyed (namely the power delivered by MOS transistors of the inverter that supplies the armature windings of the machine) between the machine and a remote control and power module by integrating the power electronics at the rear of the machine, thus making it possible to gain in reliability and safety, although the machine is placed in a very severe thermal and vibratory environment.

[0016]Moreover, the division of the management of the functioning of the machine into a high-level part and a low-level part (effected outside the machine) on the one hand and a hardware part (effected in the machine) on the other hand makes it possible to benefit from the advantages of an offset control: isolation with respect to the very severe thermal and vibratory environment, software and hardware resources easily available, great flexibility compared with the on-board system application and architectures (only one battery, two batteries in parallel, two batteries in series in particular on starting, system combining battery and supercapacitors etc). There will in fact be a single microprocessor in an offset control unit and consequently a single standard architecture whatever the nature of the on-board system of the vehicle (14V, 42V). In addition, having an offset control unit makes it possible not to be limited in terms of resources to be integrated in the said unit.

[0018]Finally, using hard-wired links makes it possible to transmit a single item of information per link whether it be digital or analogue, the said information depending on no communication protocol.

Problems solved by technology

In other words, the control of the alternator starter from outside is essentially limited to indicating to it whether it must function in starter mode or in alternator mode.

This poses problems of reliability and cost, because of the severity of the thermal and vibratory environment.

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